Summary: A Biblical overview on the issue of tithing from Abraham to Paul.
“Why Should We Tithe?”
Genesis 14:18-20 And Melchizedek king of Salem brought forth bread and wine: and he was the priest of the most high God.  And he blessed him, and said, Blessed be Abram of the most high God, possessor of heaven and earth:  And blessed be the most high God, which hath delivered thine enemies into thy hand. And he gave him tithes of all.
Leviticus 27:30 And all the tithe of the land, whether of the seed of the land, or of the fruit of the tree, is the Lord’s: it is holy unto the Lord.
Malachi 3:8-10 Will a man rob God? Yet ye have robbed me. But ye say, Wherein have we robbed thee? In tithes and offerings.  Ye are cursed with a curse: for ye have robbed me, even this whole nation.  Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the Lord of hosts, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it.
Matthew 23:23 Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone.
1 Corinthians 16:2 Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.